Working irregular hours may increase the risk of developing diabetes, according to a new study.

The study, a meta-analysis based on 12 studies involving 226 652 participants, including 14 595 who had diabetes, found that people who’ve ever had shift-work jobs have a 9% increased risk of developing diabetes compared with those who consistently worked daytime hours. The increased risk was highest, 42%, in people who worked rotating shifts involving daytime, evening, and nighttime hours.